William G. Paterson

Predictive value of the rome criteria for diagnosing the irritable bowel syndrome

Objective:Our aim was to examine the predictive value of the Rome criteria and absence of so-called “red flags” of clinical practice for diagnosing irritable bowel syndrome. Red flags were relevant abnormalities on physical examination, documented weight loss, nocturnal symptoms, blood in stools, history of antibiotic use, and family history of colon cancer.Methods:In retrospective studies, 98 patients who had one or more Rome criteria and lacked red flags were identified by chart review of a 1-yr period. In prospective studies, 95 patients were identified who met the Rome criteria and lacked red flags. Sensitivity, specificity, predictive value of Rome criteria, and absence of red flags were determined. Consultants final diagnosis was the gold standard. Investigations before and after referral were recorded and reason for referral was determined in prospective studies.Results:In the retrospective series, the Rome criteria and absence of red flags had a sensitivity of 65%, specificity of 100%, and positive predictive value of 100%. None of these patients required revision of their diagnosis during a 2-yr follow-up. In the prospective study, the positive predictive value was 98%. More than 50% of the patients in this group had been referred because of diagnostic uncertainty and 24% had had an abdominal ultrasound; 66% of those <45 yr old underwent at least partial colonic evaluation.Conclusion:These findings suggest that the Rome criteria combined with a lack of red flags have a very high predictive value for diagnosing irritable bowel syndrome. Application of these diagnostic criteria has the potential to alter utilization of health care resources.

Canadian Consensus Conference on the management of gastroesophageal reflux disease in adults - Update 2004

BACKGROUND Gastroesophageal reflux disease (GERD) is the most prevalent acid-related disorder in Canada and is associated with significant impairment of health-related quality of life. Since the last Canadian Consensus Conference in 1996, GERD management has evolved substantially. OBJECTIVE To develop up-to-date evidence-based recommendations relevant to the needs of Canadian health care providers for the management of the esophageal manifestations of GERD. CONSENSUS PROCESS A multidisciplinary group of 23 voting participants developed recommendation statements using a Delphi approach; after presentation of relevant data at the meeting, the quality of the evidence, strength of recommendation and level of consensus were graded by participants according to accepted principles. OUTCOMES GERD applies to individuals who reflux gastric contents into the esophagus causing symptoms sufficient to reduce quality of life, injury or both; endoscopy-negative reflux disease applies to individuals who have GERD and a normal endoscopy. Uninvestigated heartburn-dominant dyspepsia - characterised by heartburn or acid regurgitation - includes erosive esophagitis or endoscopy-negative reflux disease, and may be treated empirically as GERD without further investigation provided there are no alarm features. Lifestyle modifications are ineffective for frequent or severe GERD symptoms; over-the-counter antacids or histamine H2-receptor antagonists are effective for some patients with mild or infrequent GERD symptoms. Proton pump inhibitors are more effective for healing and symptom relief than histamine H2-receptor antagonists; their efficacy is proportional to their ability to reduce intragastric acidity. Response to initial therapy - a once-daily proton pump inhibitor unless symptoms are mild and infrequent (fewer than three times per week) - should be assessed at four to eight weeks. Maintenance medical therapy should be at the lowest dose and frequency necessary to maintain symptom relief; antireflux surgery is an alternative for a small proportion of selected patients. Routine testing for Helicobacter pylori infection is unnecessary before starting GERD therapy. GERD is associated with Barretts epithelium and esophageal adenocarcinoma but the risk of malignancy is very low. Endoscopic screening for Barretts epithelium may be considered in adults with GERD symptoms for more than 10 years; Barretts epithelium and low-grade dysplasia generally warrant surveillance; endoscopic or surgical management should be considered for confirmed high-grade dysplasia or malignancy. CONCLUSION Prospective studies are needed to investigate clinically relevant risk factors for the development of GERD and its complications; GERD progression, on and off therapy; optimal management strategies for typical GERD symptoms in primary care patients; and optimal management strategies for atypical GERD symptoms, Barretts epithelium and esophageal adenocarcinoma.

Gastrointestinal promotility drugs in the critical care setting: a systematic review of the evidence.

Context Gastrointestinal promotility agents may improve tolerance to enteral nutrition, reduce gastroesophageal reflux and pulmonary aspiration, and therefore have the potential to improve outcomes of critically ill patients. Objective To systematically review and critically appraise studies of promotility agents in the critical care setting. Data Sources Computerized bibliographic search of published research (1980–2001), citation review of relevant articles, and contact with primary investigators. Study Selection Randomized trials of critically ill adult patients that evaluated the effect of promotility agents on measures of gastrointestinal motility were included. Data Extraction Relevant methods and outcome data were abstracted in duplicate by independent investigators. Data Synthesis We reviewed 60 citations; 18 articles met the inclusion criteria (six studies of feeding tube placement, 11 studies evaluating gastrointestinal function, and one study of clinical outcomes). The heterogeneity of study methods and outcomes measured precluded a quantitative synthesis of the data. Although there are conflicting studies, the larger and more methodologically robust studies suggest that metoclopramide has no effect on feeding tube placement. Erythromycin has been shown to increase success rates with small-bowel tube placement in two studies. Eight of ten studies evaluating the effect of cisapride, metoclopramide, or erythromycin on measures of gastrointestinal transit demonstrated positive effects; the two studies that did not were relatively small (n = 27 and 10) and likely had inadequate power to detect a difference in treatment effect. No study demonstrated a positive effect on clinical outcomes. Conclusions As a class of drugs, promotility agents appear to have a beneficial effect on gastrointestinal motility in critically ill patients. A one-time dose of erythromycin may facilitate small-bowel feeding tube insertion. Administration of metoclopramide appears to increase physiologic indexes of gastrointestinal transit and feeding tolerance. Concerns about safety and lack of effect on clinically important outcomes preclude strong treatment recommendations.

The Toronto Consensus Statements for the Management of Inflammatory Bowel Disease in Pregnancy

BACKGROUND & AIMS The management of inflammatory bowel disease (IBD) poses a particular challenge during pregnancy because the health of both the mother and the fetus must be considered. METHODS A systematic literature search identified studies on the management of IBD during pregnancy. The quality of evidence and strength of recommendations were rated using the Grading of Recommendation Assessment, Development and Evaluation (GRADE) approach. RESULTS Consensus was reached on 29 of the 30 recommendations considered. Preconception counseling and access to specialist care are paramount in optimizing disease management. In general, women on 5-ASA, thiopurine, or anti-tumor necrosis factor (TNF) monotherapy for maintenance should continue therapy throughout pregnancy. Discontinuation of anti-TNF therapy or switching from combination therapy to monotherapy may be considered in very select low-risk patients. Women who have a mild to moderate disease flare while on optimized 5-ASA or thiopurine therapy should be managed with systemic corticosteroid or anti-TNF therapy, and those with a corticosteroid-resistant flare should start anti-TNF therapy. Endoscopy or urgent surgery should not be delayed during pregnancy if indicated. Decisions regarding cesarean delivery should be based on obstetric considerations and not the diagnosis of IBD alone, with the exception of women with active perianal Crohns disease. With the exception of methotrexate, the use of medications for IBD should not influence the decision to breast-feed and vice versa. Live vaccinations are not recommended within the first 6 months of life in the offspring of women who were on anti-TNF therapy during pregnancy. CONCLUSIONS Optimal management of IBD before and during pregnancy is essential to achieving favorable maternal and neonatal outcomes.

Standardization of a simplified scintigraphic methodology for the assessment of gastric emptying in a multicenter setting

OBJECTIVE:Scintigraphy remains the gold standard to study gastric emptying. The technique is onerous and normal values vary between centers. Standardized protocols, although desirable, are not presently available. We validated a simplified scintigraphic protocol in a multicenter setting.METHODS:In 69 healthy volunteers from seven Canadian institutions, gastric emptying of a standard meal (99mTc- labeled beef liver) was assessed by scintigraphy every 10 min for 1 h, then every 20 min for the next 2 h. Gastric retention was fitted to a power exponential model, Propt={−(κt)β} with Propt= proportion of retention at time t, either using all 13 time intervals (conventional technique) or using measurements at 0, 1, 2, and 3 h (simplified technique).RESULTS:The power exponential model yielded identical emptying curves and T ½ values with both techniques. Gastric emptying was more rapid in men than in women < 35 yr (p < 0.01) and in younger than in older men (p < 0.005). Gastric emptying was slower in women from Québec than in women from Ontario (p < 0.04). Gastric retention was similar at 1, 2, and 3 h among the seven centers. Gastric emptying of a beef liver meal was slower than that of a low fat egg substitute (p < 0.03).CONCLUSIONS:A simpler scintigraphic approach, using four rather than 13 samples, provides results comparable to those of the conventional technique. This simpler approach provides an economical, yet accurate, alternative to the techniques presently used and is applicable to a multicenter setting.

The IBS-36: A new Quality of Life measure for irritable bowel syndrome

OBJECTIVE:We aimed to develop and validate a quality of life instrument for patients with irritable bowel syndrome (IBS).METHODS:Using focus groups, existing questionnaires, and literature reviews, five IBS patients and nine gastroenterologists compiled and pilot tested for content validity a 70-item questionnaire. The questionnaire was then administered to 107 IBS patients, and using these data, the 70-item questionnaire was reduced to 36 questions through statistical and consensus methodology. The IBS-36 questionnaire was tested for construct validity, reliability, reproducibility, and responsiveness using a gold standard of structured interviews by three gastroenterologists, the Medical Outcomes Study Short Form Quality of Life Questionnaire, and the Coping Resource Inventory.RESULTS:The IBS-36 consists of 36 questions scored on a 7-point Likert scale. It has a very high internal consistency (Cronbachs α= 0.95) and a high test-retest reliability (Spearmans r= 0.92) and correlates as hypothesized with the Medical Outcomes Study Short Form Quality of Life Questionnaire (p < 0.001), McGill pain scores (p < 0.001), and IBS patient-reported sleep, symptom, and pain scores (ps = 0.030, <0.001, and <0.001, respectively).CONCLUSIONS:The IBS-36 addresses all areas of quality of life affected by IBS and is easy to administer and score. The IBS-36 is a well-validated, condition-specific quality of life measure for IBS patients that is sensitive to clinical intervention and highly correlated with established quality of life measures and patient-reported symptom scores.

Esophageal shortening induced by short-term intraluminal acid perfusion in opossum: A cause for hiatus hernia?

BACKGROUND/AIMS Reflux esophagitis and hiatal hernia commonly coexist, yet a cause and effect relationship remains unclear. This study examined whether acute acid-induced esophageal injury induces longitudinal esophageal shortening in the opossum model. METHODS Esophageal length was measured continuously using a specially designed strain gauge transducer in anesthetized opossums while the midesophagus was perfused intraluminally with either normal saline or 100 mmol/L HCl. After a stabilization period, the test solution was perfused for 150 minutes. The effect of bilateral cervical vagotomy and atropine (60 microns/kg intravenously) were determined in separate groups. Parallel studies in which resting lower esophageal sphincter pressure was measured before and after prolonged intraesophageal acid perfusion were performed. RESULTS Esophageal acid perfusion induced acute epithelial injury as determined histologically. This was associated with significant esophageal shortening compared with saline-perfused controls and was not affected by vagotomy or atropine. In contrast, acid perfusion invariably induced a decrease in resting lower esophageal sphincter pressure. CONCLUSIONS Acute acid-induced esophageal mucosal injury induces longitudinal esophageal shortening that does not involve vagal pathways or cholinergic neurons. This raises the possibility that esophagitis could contribute to the development of hiatal hernia by inducing esophageal long axis shortening.

Canadian Consensus on Medically Acceptable Wait Times for Digestive Health Care

BACKGROUND Delays in access to health care in Canada have been reported, but standardized systems to manage and monitor wait lists and wait times, and benchmarks for appropriate wait times, are lacking. The objective of the present consensus was to develop evidence- and expertise-based recommendations for medically appropriate maximal wait times for consultation and procedures by a digestive disease specialist. METHODS A steering committee drafted statements defining maximal wait times for specialist consultation and procedures based on the most common reasons for referral of adult patients to a digestive disease specialist. Statements were circulated in advance to a multidisciplinary group of 25 participants for comments and voting. At the consensus meeting, relevant data and the results of voting were presented and discussed; these formed the basis of the final wording and voting of statements. RESULTS Twenty-four statements were produced regarding maximal medically appropriate wait times for specialist consultation and procedures based on presenting signs and symptoms of referred patients. Statements covered the areas of gastrointestinal bleeding; cancer confirmation and screening and surveillance of colon cancer and colonic polyps; liver, biliary and pancreatic disorders; dysphagia and dyspepsia; abdominal pain and bowel dysfunction; and suspected inflammatory bowel disease. Maximal wait times could be stratified into four possible acuity categories of 24 h, two weeks, two months and six months. FUTURE DIRECTIONS Comparison of these benchmarks with actual wait times will identify limitations in access to digestive heath care in Canada. These recommendations should be considered targets for future health care improvements and are not clinical practice guidelines.

Role of mast cell-derived mediators in acid-induced shortening of the esophagus

It has recently been demonstrated that acid-induced esophageal mucosal injury leads to esophageal shortening, raising the possibility that reflux esophagitis per se may contribute to the development of hiatal hernia. The aim of the present study was to determine whether mast cell-derived mediators are involved in this acid-induced esophageal shortening. Changes in esophageal length were continuously monitored in anesthetized opossums while the esophageal lumen was perfused with 100 mmol/l HCl or normal saline. Changes in esophageal length were compared between animals perfused with acid, with or without pretreatment with the mast cell stabilizers doxantrazole or disodium cromoglycate (DSCG), and animals perfused with normal saline, with or without pretreatment with DSCG. In separate in vitro studies the effect of the mast cell stabilizers on electrical field stimulation-induced esophageal longitudinal muscle contraction was determined. Gradual esophageal lengthening occurred during saline perfusion, irrespective of whether animals were pretreated with DSCG. In contrast, acid perfusion induced esophageal shortening, which was abolished by pretreatment with either doxantrazole or DSCG in doses sufficient to attenuate the acid-induced mucosal histamine release. In vitro, the mast cell stabilizers had no effect on electrical field stimulation-induced esophageal shortening. This study suggests that esophageal shortening associated with acute acid-induced esophageal mucosal injury in the opossum is dependent on mast cell-derived mediators.It has recently been demonstrated that acid-induced esophageal mucosal injury leads to esophageal shortening, raising the possibility that reflux esophagitis per se may contribute to the development of hiatal hernia. The aim of the present study was to determine whether mast cell-derived mediators are involved in this acid-induced esophageal shortening. Changes in esophageal length were continuously monitored in anesthetized opossums while the esophageal lumen was perfused with 100 mmol/l HCl or normal saline. Changes in esophageal length were compared between animals perfused with acid, with or without pretreatment with the mast cell stabilizers doxantrazole or disodium cromoglycate (DSCG), and animals perfused with normal saline, with or without pretreatment with DSCG. In separate in vitro studies the effect of the mast cell stabilizers on electrical field stimulation-induced esophageal longitudinal muscle contraction was determined. Gradual esophageal lengthening occurred during saline perfusion, irrespective of whether animals were pretreated with DSCG. In contrast, acid perfusion induced esophageal shortening, which was abolished by pretreatment with either doxantrazole or DSCG in doses sufficient to attenuate the acid-induced mucosal histamine release. In vitro, the mast cell stabilizers had no effect on electrical field stimulation-induced esophageal shortening. This study suggests that esophageal shortening associated with acute acid-induced esophageal mucosal injury in the opossum is dependent on mast cell-derived mediators.

Ambulatory esophageal manometry, pH-metry, and holter ECG monitoring in patients with atypical chest pain

Standard Holter electrocardiographic (ECG) monitoring was combined with ambulatory esophageal manometry and pH-metry in 25 patients with atypical chest pain in order to determine whether an association could be found between spontaneous pain episodes and ischemic ECG changes or esophageal dysfunction. Results of ambulatory testing were compared to those obtained with standard esophaeal manometry and provocative testing. Twenty-two of the 25 patients experienced a total of 88 pain episodes during ambulatory testing. Although 15 of the 22 patients (68%) experiencing pain during testing had at least one pain episode that corelated temporally with gastroesophageal reflux, esophageal dysmotility or ischemic ECG changes, 65% of all pain episodes were unrelated to abnormal esophageal events or ECG changes. Seventeen percent of pain episodes were associated with gastroesophageal reflux, 15% with esophageal dysmotility,and 2% with a combined acid reflux and esophageal dysmotility event. Only one pain episode was associated with ischemic ECG changes. Twelve of the 15 patients with chest pain episodes associated with reflux or esophageal dysmotility had othe identical pain episodes in which there was no correlation. Reproduction of a patients pain during standard manometry with provocative testing did not predict a strong correlation between the patients spontaneous pain episodes and esophageal dysfunction during ambulatory recordings. In summary, patients with atypical chest pain have relatively few spontaneous pain episodes that correlate with gastroesophageal reflux, esophageal dysmotility, or ischemic ECG changes. It appears that different stimuli can trigger identical episodes of chest pain, which suggests that many of these patients may have dysfunction of their visceral pain sensory mechanisms.